Mass Treatment with Single-Dose Azithromycin for Trachoma

Abstract

Background Trachoma, caused by repeated ocular infection with Chlamydia trachomatis, is an important cause of blindness. Current recommended dosing intervals for mass azithromycin treatment for trachoma are based on a mathematical model. Methods We collected conjunctival swabs for quantitative polymerase-chain-reaction assay of C. trachomatis before and 2, 6, 12, 18, and 24 months after mass treatment with azithromycin in a Tanzanian community in which trachoma was endemic. For ethical reasons, at 6, 12, and 18 months, we gave tetracycline eye ointment to residents who had clinically active trachoma. Results At baseline, 956 of 978 residents (97.8 percent) received either one oral dose of azithromycin or (if azithromycin was contraindicated) a course of tetracycline eye ointment. The prevalence of infection fell from 9.5 percent before mass treatment to 2.1 percent at 2 months and 0.1 percent at 24 months. The quantitative burden of ocular C. trachomatis infection in the community was 13.9 percent of the pretreatment level at 2 months and 0.8 percent at 24 months. At each time point after baseline, over 90 percent of the total community burden of C. trachomatis infection was found among subjects who had been positive the previous time they were tested. Conclusions The prevalence and intensity of infection fell dramatically and remained low for two years after treatment. One round of very-high-coverage mass treatment with azithromycin, perhaps aided by subsequent periodic use of tetracycline eye ointment for persons with active disease, can interrupt the transmission of ocular C. trachomatis infection.

Mass administration of azithromycin andStreptococcus pneumoniaecarriage: cross-sectional surveys in the Gambia

“…4 However, evidence from the Gambia and the United Republic of Tanzania indicates that three rounds are unnecessary in low prevalence settings. [5][6][7][8] In such situations, repeated azithromycin MDA may be detrimental if it results in the selection of macrolideresistant pathogens. Although currently there is no evidence that repeated MDA increases the prevalence of azithromycinresistant C. trachomatis, 9 there is epidemiological evidence suggesting that pharyngeal carriage of macrolide-resistant Streptococcus pneumoniae increases following repeated MDA for trachoma control.…”

Association of Mass Treatment with Azithromycin in Trachoma-Endemic Communities with Short-Term Reduced Risk of Diarrhea in Young Children

“…1,2 Results from studies conducted in areas with a high burden of trachoma show that a single dose of azithromycin is effective in treating chlamydial infections and preventing their recurrence. [3][4][5] Mass distribution of azithromycin (MDA) in trachoma-endemic communities has been adopted as a part of World Health Organization (WHO)-endorsed, multi-pronged strategy for reducing the risk of blindness in national trachoma control programs. 6,7 In addition to C. trachomatis, evidence from laboratory and experimental studies indicate that azithromycin is effective against infections caused by a broad spectrum of parasites and bacteria, including those pathogens responsible for sexually transmitted infections, acute respiratory infections, possibly malaria and bacterial enteric infections, which are prevalent in developing countries.…”

Trachoma as cause of blindness: literature review

“…Despite the limited evidence in randomized trials, the overwhelming evidence from cohort studies, the rate of clinical disease and infection rates fall after the mass distribution of antibiotics (39)(40)(41)(42)(43). The mass distribution is indicated when the proportion of children aged 1-9 years with follicular trachoma (TF) is more than 10% in assessed community.…”